The present invention relates to an apparatus for material surface observation, and especially to a scanning electron microscope preferable for observation in-situ an atomic level of a reaction at a material surface which is activated and induced by irradiation of a charged particle electromagnetic wave such as X-ray or synchrotron orbital radiation (SOR), an energetic beam such as a laser beam or an ion beam etc.
Currently, research on material characteristics of a solid surface has advanced rapidly owing to practical use of a scanning tunnel microscope (STM), etc., and to improvement in resolving power of a scanning electron microscope (SEM) reaching to several .ANG., which has made it possible to observe the solid surface such as a specific atomic configuration, etc., at an atomic level.
However, even though the conventional apparatus described above has made it possible to observe a stable surface condition before and after a reaction, observation of a transient reaction process has been impossible.
That is, as the conventional apparatus described above has not been provided with an apparatus to activate the surface of the sample during surface observation, the observation of the surface only after a reaction or the surface of a stable condition before the reaction has been possible, and measurement of an activated or a stable condition of the surface in the reaction process in the aspect of an atomic arrangement, or in-site observation of the reaction of a surface atom with an atmospheric atom (a surface reaction), etc. have been impossible.
An apparatus combining a transmission electron microscope with an ion accelerator for in-situ observation of a lattice defect generated in a sample by irradiation of ions has been disclosed in JP-A-62-31930 (1987).
Nevertheless, it is impossible to observe a reaction process at a solid surface in-situ even with the transmission electron microscope.